Surfing is an extremely old sport. Lieutenant James King, serving under Captain James Cook during his third expedition to the Pacific, in 1779 wrote what is recognized as the first known written description of the surfing ever recorded by Western man. Referring to the locals at Kealakekua Bay on the Kona coast of the Big Island of Hawaii, King writes:
Whenever, from stormy weather, or any extraordinary swell at sea, the impetuosity of the surf is increased to its utmost heights, they choose that time for this amusement: twenty or thirty of the natives, taking each a long narrow board, rounded at the ends, set out together from the shore. . . . As the surf consists of a number of waves, of which every third is remarked to be always much larger than the others, and to flow higher on the shore, the rest breaking in the intermediate space, their first object is to place themselves on the summit of the largest surge, by which they are driven along with amazing rapidity toward the shore.
Since the time of the ancient Hawaiians, surfing has evolved considerably. While the Hawaiians rode wooden surfboards that could weigh as much as 175 pounds, in contrast, modern surfboards are much smaller, lighter and more maneuverable.
Modern surfboards are rarely made of solid wood. Instead, a modern surfboard is usually made of shaped and sanded foam that has been covered with one or more layers of fiberglass. For example, FIG. 1 shows a typical prior art modern surfboard 10. A body of shaped plastic foamed material 11 is covered with a layer of fiber-reinforced resin 12, preferably fiberglass, and has one or more fins which are supported in a rectangular box called a fin box. On some surfboards, the fins are xe2x80x9cglassed onxe2x80x9d for support.
Glassing the fins onto a surfboard refers to the act of attaching the fins to the board by means of a fiber-reinforced resin around the base of the fin. There are significant disadvantages to glassing the fins onto the surfboard. Labor costs can be high and subsequent sanding and finishing of the board can be difficult. Also, once the fin is glassed on, it cannot be adjusted or replaced. Hence, transporting a surfboard with glassed on fins can be difficult. For example, if the fin is bumped or hit it can break off or crack the fiberglass, ruining the whole surfboard.
In the use of the fin box, a rectangular cavity is formed in the board by the use of a router and the fin box is inserted into this cavity. FIG. 2 shows a side cross section view of fin box 14 shown in FIG. 1. Fin box 14 is initially secured inside the cavity in foamed material 11 by an adhesive and then further secured by fiber-reinforced resin layer 12. Fin 13 is inserted inside fin box 14 and secured into fin box 14 by means of screw 15. To remove fin 13 from fin box 14, the surfer has to unscrew screw 15 with a screwdriver.
There are significant disadvantages to prior art fin boxes. For example, the screw can corrode due to long term exposure to salt water. Or the screw can loosen over time, allowing the fin to fall out and become lost. Also, because a tool is required to remove the fin, a surfer who does not have a screwdriver with him will be unable to remove his fin.
Whereas ancient Hawaiians surfed primarily for pleasure or social status, modern surfing can be extremely competitive. Surfing competitions are held throughout the world with world wide television coverage and large cash prizes. Also, valuable endorsement contracts are rewarded to the best surfers.
Competitive surfers are looking for an advantage over the field to increase their odds of winning. The board and fin types chosen by the surfer are very important. Based on the wave conditions, one type of fin may be preferable over another type. Currently, it is difficult for the surfer to quickly switch fins. He is forced to find a screwdriver, unscrew the current fin, and screw in the new fin.
What is needed is a better way of mounting fins into a fin box.
The present invention provides a surfing craft with removable fin. A removable fin is disposed in a fin box and the fin box is disposed in a surfing craft body. A releasable locking mechanism has a spring actuated locking arm, a locking tab and an indention. The spring actuated locking arm applies spring force for locking the locking tab into the indention. A counter force is applied to the spring actuated locking arm to remove the fin from the fin box. In one preferred embodiment, the locking tab is attached to the locking arm and the locking arm is bendably connected to the fin. In this preferred embodiment the indention is on the fin box and the locking arm""s locking tab is engaged with the indention of the fin box to prevent the fin from disconnecting from the fin box. Also in this preferred embodiment, by applying finger force the locking arm is bent causing the locking tab to disengage the indention so that the fin can be removed.